We present a generally applicable theory of focusing based on the hypothesis that a person focuses more on, and hence overweights, attributes in which her options differ more. Our model predicts that the decision maker is too prone to choose options with concentrated advantages relative to alternatives, but maximizes utility when the advantages and disadvantages of alternatives are equally concentrated. Applying our model to intertemporal choice, these results predict that a person exhibits present bias and time inconsistency when—such as in lifestyle choices and other widely invoked applications of hyperbolic discounting—the future effect of a current decision is distributed over many dates, and the effects of multiple decisions accumulate. But unlike in previous models, in our theory (1) present bias is lower when the costs of current misbehavior are less dispersed, helping explain why people respond more to monetary incentives than to health concerns in harmful consumption; and (2) time inconsistency is lower when a person commits to fewer decisions with accumulating effects in her ex ante choice. In addition, a person does not fully maximize welfare even when making decisions ex ante: (3) she commits to too much of an activity—for example, exercise or work—that is beneficial overall; and (4) makes “future-biased” commitments when—such as in preparing for a big event—the benefit of many periods’ effort is concentrated in a single goal.

We use data from Hungary to establish two results about the relationship between the government and the media. (i) We document large advertising favors from the government to connected media, and large corruption coverage favors from connected media to the government. Our empirical strategy exploits sharp reallocations around changes in media ownership and other events to rule out market‐based explanations. (ii) Under the assumptions of a structural model, we distinguish between owner ideology and favor exchange as the mechanism driving favors. We estimate our model exploiting within‐owner changes in coverage for identification and find that both mechanisms are important. These results imply that targeted government advertising can meaningfully influence content. Counterfactuals show that targeted advertising can also influence owner ideology, by making media ownership more profitable to pro‐government connected investors. Our results are consistent with qualitative evidence from many democracies and suggest that government advertising affects media content worldwide.

We model populism as the dissemination of a false “alternative reality,” according to which the intellectual elite conspires against the populist for purely ideological reasons. If enough voters are receptive to it, this alternative reality—by discrediting the elite's truthful message—reduces political accountability. Elite criticism, because it is more consistent with the alternative reality, strengthens receptive voters' support for the populist. Alternative realities are endogenously conspiratorial to resist evidence better. Populists, to leverage or strengthen beliefs in the alternative reality, enact harmful policies that may disproportionately harm the non-elite. These results explain previously unexplained facts about populism.

We created experimental variation across markets in China in the share of firms having access to a new loan product. Access to finance had a large positive direct effect on the performance of treated firms but a similar-sized negative indirect effect on that of firms with treated competitors, leading to nondetectable gains in producer surplus. Access to finance had a positive direct effect on business quality and consumer satisfaction and a negative effect on price, which were not offset by indirect effects, implying net gains in consumer surplus. We document other indirect effects and combine effects in a welfare evaluation.

Accepted Manuscript

We organized business associations for the owner-managers of young Chinese firms to study the effect of business networks on firm performance. We randomized 2,820 firms into small groups whose managers held monthly meetings for one year, and into a "no-meetings" control group. We find the following. (i) The meetings increased firm revenue by 8.1%, and also significantly increased profit, factors, inputs, the number of partners, borrowing, and a management score. (ii) These effects persisted one year after the conclusion of the meetings. (iii) Firms randomized to have better peers exhibited higher growth. We exploit additional interventions to document concrete channels. (iv) Managers shared exogenous business-relevant information, particularly when they were not competitors, showing that the meetings facilitated learning from peers. (v) Managers created more business partnerships in the regular than in other one-time meetings, showing that the meetings improved supplier-client matching.

We analyze the implications of household-level adjustment costs for the dynamics of aggregate consumption. We show that an economy in which agents have “consumption commitments” is approximately equivalent to a habit formation model in which the habit stock is a weighted average of past consumption if idiosyncratic risk is large relative to aggregate risk. Consumption commitments can thus explain the empirical regularity that consumption is excessively sensitive and excessively smooth, findings that are typically attributed to habit formation. Unlike habit formation and other theories, but consistent with empirical evidence, the consumption commitments model also predicts that excess sensitivity and smoothness vanish for large shocks. These results suggest that behavior previously attributed to habit formation may be better explained by adjustment costs. We develop additional testable predictions to further distinguish the commitment and habit models and show that the two models have different welfare implications.

We estimate a model of importers in Hungarian microdata and conduct counterfactual analysis to investigate the effect of imported inputs on productivity. We find that importing all input varieties would increase a firm’s revenue productivity by 22 percent, about one-half of which is due to imperfect substitution between foreign and domestic inputs. Foreign firms use imports more effectively and pay lower fixed import costs. We attribute one-quarter of Hungarian productivity growth during the 1993–2002 period to imported inputs. Simulations show that the productivity gain from a tariff cut is larger when the economy has many importers and many foreign firms.

We develop a model in which connections between individuals serve as social collateral to enforce informal insurance payments. We show that: (i) The degree of insurance is governed by the expansiveness of the network, measured with the per capita number of connections that groups have with the rest of the community. “Two-dimensional” networks—like real-world networks in Peruvian villages—are sufficiently expansive to allow very good risk-sharing. (ii) In second-best arrangements, insurance is local: agents fully share shocks within, but imperfectly between endogenously emerging risk-sharing groups. We also discuss how endogenous social collateral affects our results.

We show that characterizing the effects of housing on portfolios requires distinguishing between the effects of home equity and mortgage debt. We isolate exogenous variation in home equity and mortgages by using differences across housing markets in house prices and housing supply elasticities as instruments. Increases in property value (holding home equity constant) reduce stockholdings, while increases in home equity wealth (holding property value constant) raise stockholdings. The stock share of liquid wealth would rise by 1 percentage point—6% of the mean stock share—if a household were to spend 10% less on its house, holding fixed wealth.